The use of a rotary steel rule die apparatus for paperboard die-cutting is well-known. Such apparatus comprises a die cylinder, having a die board, and an anvil roll positioned parallel to the die cylinder so as to define a sheet receiving gap therebetween. The die board is provided with steel rules so mounted to the board in a press-fitted way as to yield a predetermined shape to the sheet to cut, which can be a corrugated board or other sheet materials. The assembly of rules which yields the predetermined shape cut in the sheet will be referred to herein as the die cutting pattern or matrix.
It is a common practice in the field of steel rule die cutting to provide a width of about ½″ (1.27 cm) of extra sheet beyond the rules on all sides except on the front side where an extra width of about ¼″ (0.63 cm) is provided. This extra width is provided to prevent centering problem of the sheet, and to help ejecting the trim.
Currently in the paperboard die-cutting industry, a major part of the waste in the die-cutting operation of corrugated carton relates to the trim around the carton's pattern.
A rotary steel rule die apparatus which would allow minimizing the trim around the carton's pattern is thus desirable.